Positron Emission Tomography (PET) can be used to measure glucose utilization in human tumors. Since rapidly growing poorly differentiated neoplasms have higher rates of glycolysis than slow growing well differentiated neoplasms, PET scanning may be used to categorize the degree of malignancy. It has already been used to predict survival time in glioma patients and it has been used to image glucose utilization in extremity soft-tissue sarcomas. Since no study has correlated glucose utilization rate in extremity sarcomas with histologic grade or clinical outcome, the present study will attempt to answer the following questions: 1. Can PET scan results be used to estimate glucose utilization rates reproducibly? 2. Do PET scan results of glucose utilization rates correlate with histopathology as read in the Department of Pathology? 3. What is the glucose 6-phosphatase level of fresh human tumor after recection of extremity sarcomas? 4. What is the fresh glucose 6-phosphatase activity of human muscle from extremity sarcoma specimens? Patients will be studied for resting energy expenditure by the method of indirect calorimetry. This will help gather information about any distant metabolic effects produced by soft-tissue sarcomas resulting in abnormal glucose metabolism.